1. Field of Invention
The present invention relates to haemodialysis equipment in general, and more particularly relates to container bags for powdery saline compounds for the preparation of a liquid concentrate used in haemodialysis machines. The present invention also relates to the use of a manufacturing procedure that provides a compartmented bag for haemodialysis machines. A primary object of the invention is to provide a bag assembly that avoids the use of inner solution suction tubing. Such inner solution suction tubing, which carries a tubular filter mounted at the end, has been used in prior embodiments to preclude the dissolving powder from migrating out of the device before the powder is dissolved.
A further object of this invention resides in providing a system designed for the above objective which, due to its particular structure that divides the inside of the bag into two chambers, functions to prevent the powder in one of them from leaking during the handling prior to its being connected to the dialysis machine.
The invention solves these problems by providing a bicompartment bag having an assembly of two strong flexible outer sheets with an access bushing affixed through one of the sheets. The invention also provides a process of manufacturing the bicompartment bag.
In order to solve the aforementioned problems, the invention replaces the above-described prior art filter with a microperforated sheet to prevent the undissolved powder from leaking. The microperforated sheet acts as a partition between a first zone or chamber where the undissolved powder is stored and a second chamber through which the solution exits. The prior art entrance filter is replaced in the present invention by a cross-shaped valve-like device built into the stopper.
The advantages of the present invention are as follows:                a) Lower cost due to the elimination of the above-described filters and exit tube for the solution mixed in the bag,        b) Insertion of the separating sheet defining two chambers;        c) Addition of a draining sheet in the exit chamber, which adopts a tie-like configuration, and which, due to its irregular surface, enables the liquid to be drained between the two plastic sheets defining the chamber, such that by flowing through the microperforated zone the liquid easily drains toward the outlet port and        d) Assembling the container in a single procedure at the production plant, with the consequent labour reduction resulting from the lesser number of operations to conduct.        
Finally, the only operations to be carried out at the production plant are the testing, filling and sealing with a simple stopper, with no need to pre-assemble the discharge tube with its filter and positioning the inlet filter, this being a feature of the invention that minimizes the operative procedures required.
In summary, the invention further provides a new, extremely simple constructive procedure, to make it suitable to optimally attain its objects, including providing a means to divide the container into two separate chambers, in one of which the powdered product to be converted into a concentrate used in haemodialysis is to be stored.
2. Description of the Prior Art
Bags prepared to contain the salt used to achieve the saline concentrate to be used in haemodialysis machines, consisting, e.g., of sodium bicarbonate (NaHCO3), for dialysis carried out with such bicarbonate, are known in the previous art.
The most widespread bag is built from a tubular thermoplastic material sleeve, the coupling bearing of which must be inserted through one of the sleeves ends to be positioned such that it projects through a circular orifice around which it must be carefully sealed. On this portion, a second coupling component member must be affixed. Due to this type of construction, the bag must be then filled with the powder, with the ensuing risk of fouling the plastic film or sheet with the powder product, thus causing a defective sealing of the bag. As a consequence thereof, it is not possible to test the already full bag for water-tightness, which is the main drawback of this kind of element, apart from the difficulties encountered when assembling these pieces, which pieces need to be individually hand-made.
This construction was followed by a significant improvement, wherein said bearing or bushing is comprised of two portions including the lid, for which there has been a commonly owned Argentinian patent application filed under No. P 010104208, covering a system for haemodialysis bags consisting of a pair of members: one first annular member attached to the bag and a second member connectable with the first one communicating the outside and inside of the bag, wherein it extends by means of a conduct coupled to a tubing extending toward the bottom of the bag, and including a special filter on one end, for the purpose of avoiding the undissolved particles to be entrained in the solution being withdrawn.
In the previous art, the petitioner further owns Argentinian patents Nos. 229,630 and 235,076, each relating to a preserver Bag, No. 251,932 to a Serum flask and No. AR011468 to a Sterile connector. EP 0278100, referring to a system to prepare a medicinal fluid by mixing at least one powder in water and a cartridge to be used therewith is also known in this field. The cartridge it refers to is different from this invention and it can only be considered as a previous step not forestalling the new construction.
It is worth mentioning that there are other numerous patents and utility models in the field of the present invention in several countries, partly by the petitioner, such as DE 92 17 989 U1, DE 91 12 569 U1, DE 38 44 174 A1, DE 88 13 659 U1, DE 86 33 262 U1, etc., which would be too unduly lengthy to enumerate, since they cover different aspects of the subject matter.